a. Field of the Invention
The present disclosure is directed to an apparatus and a method for inspecting the inner surface of a tubular structure for contamination. More particularly, the present disclosure is directed to an apparatus and method for inspecting the inner surface of a tubular structure, such as, for example, a fluid conduit for use in fuel delivery systems, for contamination resulting from the manufacture or processing of the tubular structure.
b. Background Art
Fluid delivery systems, such as, for example, vehicular fuel delivery systems, are often comprised of one or more tubularly-shaped fluid conduits each having an inner passageway that allows for the communication of fluid from a source to one or more components downstream from the source. For example, a vehicular fuel delivery system may comprise one or more fluid conduits commonly known as fuel rails that are configured to allow for the communication of fuel from a fuel tank to one or more fuel injectors. These fluid conduits may have any number of cross-sectional shapes, such as, for example and without limitation, circular, square, and rectangular, among others.
In order to avoid the creation of defects in the conduit, care must be taken during the manufacturing process to ensure that the inner surface of the conduit is free, or at least substantially free, from contaminants. For example, the inner surface of the conduit may be contaminated with residue remaining as a result of the processing of the conduit. More particularly, one type of contamination is pilgering oil that has been baked into the inner surface of the conduit. This oil is not easily removed and if the residue is brazed during a brazing operation performed on the conduit, it may create undesirable braze defects in the conduit.
Accordingly, the conduit must be inspected during the manufacturing process to ensure that the inner surface of the conduit is not unacceptably contaminated. One conventional way in which the conduit may be inspected is by visual inspection. Such a technique involves an individual performing a visual inspection from an end of a conduit with or without additional illumination. Another conventional inspection technique involves the use of a boroscope. In such a technique, a boroscope may be inserted into the conduit and may be used to inspect the inner surface thereof. Yet still another conventional technique for inspecting the inner surface of fluid conduits comprises cutting open a sampling of conduits from a given lot of conduits and visually inspecting the cut-down conduits. Based on the visual inspection of those conduits, a determination can be made as to the likelihood that the other conduits in the lot are unacceptably contaminated.
Conventional techniques, such as, for example, those described above, are not without their disadvantages, however. For example, the visual inspection technique where an individual looks down the conduit from one end thereof typically results in only identifying grossly contaminated tubes, or making a determination as to the contamination based on very limited portions of the conduit, namely those portions located proximate each end thereof. This technique is also very subjective and is dependent upon the particular individual inspecting the conduits. Accordingly, if multiple individuals are inspecting the conduits, the inspection and determinations are not necessarily uniform or consistent.
With respect to the use of a boroscope, this approach is very resource intensive. More particularly, this particular technique is time consuming and includes the use of fibers and lenses that wear down over time and, as a result, have to be replaced relatively frequently, which can be relatively expensive. Additionally, and as with the visual inspection technique described above, this technique is also very subjective and is dependent upon the particular individual inspecting the conduits. Accordingly, if multiple individuals are inspecting the conduits, the inspection and determinations are not necessarily uniform or consistent.
With respect to the technique where a sampling of conduits is cut down and inspected, and then the determinations made for those evaluated conduits are applied to other conduits in a common lot, this approach, as with those techniques described above, is relatively expensive, time consuming, and subjective. It is also ineffective unless a relatively large number of conduits are cut down and inspected.
Accordingly, there is a need for a method and system for inspecting the inner surface of tubular structures, such as, for example, fluid conduits (e.g., fuel rails), for contamination that will minimize and/or eliminate one or more of the above-identified deficiencies.